title: Simultaneous removal of cadmium and sulfamethoxazole from aqueous solution by rice straw biochar.
abstract: The simultaneous sorption behavior and characteristics of cadmium (Cd) and sulfamethoxazole (SMX) on rice straw biochar were investigated. Isotherms of Cd and SMX were well modeled by the Langmuir equation (R(2)>0.95). The calculated maximum adsorption parameter (Q) of Cd was similar in single and binary systems (34129.69 and 35919.54 mg/kg, respectively). However, the Q of SMX in a binary system (9182.74 mg/kg) was much higher than that in a single system (1827.82 mg/kg). The presence of Cd significantly promoted the sorption of SMX on rice straw biochar. When the pH ranged from 3 to 7.5, the sorption of Cd had the characteristics of a parabola pattern with maximum adsorption at pH 5, while the adsorption quantity of SMX decreased with increasing pH, with maximum adsorption at pH 3. The amount of SMX adsorbed on biochar was positively correlated with the surface area of the biochar, and the maximum adsorption occurred with d 250 biochar (biochar with a diameter of 150-250 μm). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) showed that the removal of Cd and SMX by rice straw biochar may be attributed to precipitation and the formation of surface complexes between Cd or SMX and carboxyl or hydroxyl groups. The results of this study indicate that rice straw biochar has the potential for simultaneous removal of Cd and SMX from co-contaminated water.
authors.affiliation: Ministry of Education Key Laboratory of Environmental Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Han
authors.forename: Cheng-Feng
authors.initials: CF
authors.lastname: Liang
authors.forename: Ting-Qiang
authors.initials: TQ
authors.lastname: Li
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Hua-Gang
authors.initials: HG
authors.lastname: Huang
authors.forename: Xiao-E
authors.initials: XE
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry* / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D012275:Oryza; D012996:Solutions / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013420:Sulfamethoxazole / Q000737:chemistry* / Q000302:isolation & purification*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*
chemical_list: D012996:Solutions; D014874:Water Pollutants, Chemical; D002104:Cadmium; D013420:Sulfamethoxazole